I suspect there are principles basic to human social interaction that are innate, but they are only loosely linked to what most people find to be "right" and "wrong". I suspect, for example, that we all to some degree have the capacity to empathize with someone in pain, though whether their pain saddens us or delights us after that is very contextual. Things many people would consider "basic" like murder or having sex in front of one's children I suspect are entirely learned taboos given that practice in different cultures (or even western culture itself, across time) has varied pretty wildly. I think some things that come to be considered "wrong" arise from those things that we would not like if done to us, and because of our ability to empathize, we have in building societies come to see them as wrong whenever they are done. There are others (like taboos against being naked in front of others or eating shellfish, for example) that do not seem to stem from that sense, and are entirely cultural artifacts that are more likely to be specific to a particular culture and its descendants. Other than a basic ability to empathize though, I don't think we have much in the way of preprogramming on the issue.
I thought the entire point of Christianity was that people didn't have a sense of right and wrong (and hence weren't morally responsible for our actions) until a talking snake tricked Adam and Eve into eating some magic fruit?
Were born knowing how to breath, cry, swallow, and spit-up, in that exact order. That and we know the sound of are parents voice.
No, Nasor, that's a fallacious and deceptive argument used to blame God for our choices. The whole point of the 'tree' story is that humanity intentionally disobeyed. The twist you mention is similar to someone blaming his car for getting him in trouble - by doing 115 mph in a school zone.
You've separated "right and wrong" and "obeying God and disobeying God" into two separate categories. In Christianity they're one and the same.